Long-term goals: Among the current portfolio of NIDA funded training grants, none have comorbidity as a primary focus. This is striking given co-occurrence prevalence of Substance Use Disorders (SUD) with other psychiatric conditions and health conditions (e.g. diabetes), and the extent to which either SUD or the comorbid disorder can go under- or untreated in conventional treatment settings. Enhancing research expertise to improve diagnostic, treatment and prevention strategies is essential. The proposed program will develop a cadre of scientists with research expertise in comorbidity mechanisms, antecedents and correlates, diagnostics, and psychosocial and pharmacological interventions. Component objectives are to provide each trainee with a working knowledge of comorbidity research including: (a) translational science from Early Phase Clinical Trials to Community Based Participatory Research perspectives; (b) effective research strategies for comorbid conditions across populations and ethnic and cultural groups (e.g. American Indian, Hmong, Somali). Accomplishing programmatic features will capitalize on (a) the spectrum of faculty expertise providing mentoring across multiple areas, and (b) integration across training programs and departments. Key Elements: (1) Involvement of scientists and clinicians with diverse expertise and a core internal advisory group. Primary sites (4 postdoctoral trainees, 2 yrs each) are the Departments of Psychiatry (UMN Twin Cities) and Biobehavioral Health & Population Science (UMN Duluth), supported by the Psychology Department (UMTC) and other UMN entities; (2) Recruitment, including under represented group outreach, of rigorously screened PhD and MD candidates with SUD and comorbidity as primary career focus; (3) Training with an interdisciplinary mentoring team (primary & 2 secondary mentors) with complementary expertise; (4) Formal training plans with clear milestones including trainee development of an NIH application initiated in Year 1; (5) Active research, seminars, didactic course work, workshops, and development of management, ethics, and regulatory expertise; (6) Dynamic program administration entailing monitoring with enhancements and problem resolution along with continued contact with trainees after completion and; (7) Annually convened external advisory group. Resources: Mentor funding sources include NIH Institutes, NSF, Minnesota Medical Foundation, and pharmaceutical industry. Key Personnel and Primary Mentors are directors of clinics, centers, or departments with significant resources. The program focuses on trainee expertise in SUD co-occurring with psychiatric disorders (Anxiety, ADHD, Borderline, Eating, Depression, Schizophrenia, Trauma).